CN116515092A - A kind of polyester polyol and its preparation method and application - Google Patents

Abstract

The invention relates to a polyester polyol and a preparation method and application thereof, wherein the raw materials for preparing the polyester polyol comprise the following components in parts by weight: 100 parts of polybasic acid, 100-300 parts of dealcoholization, 0-0.2 part of catalyst and not equal to 0 part; the hydroxyl value of the polyester polyol is 250-500KOH/g. The polyester polyol single kettle has high production quantity, stable product performance and high production efficiency, and can be used as raw materials of polyurethane rigid foam, adhesive and the like. The polyester polyols of the present invention based on dealcoholization are capable of providing close reactivity, foam density, foam mechanical strength and oxygen index when used in polyurethanes as compared to prior art industrial use of polyester polyols without aqueous raw materials.

Description

A kind of polyester polyol and its preparation method and application

technical field

The invention relates to the technical field of polymer chemistry, in particular to a polyester polyol and its preparation method and application.

Background technique

The production of polyester polyols includes two stages of esterification and polycondensation. In order to speed up the reaction process, increase the molecular weight of the product, reduce the acid value (usually the acid value is required to be less than 1mgKOH/g), and prevent yellowing of the polyester color, usually A vacuum of 0.1-10 kPa is used during the polycondensation stage. However, this operation will inevitably make some polyol small molecules and by-product water be extracted from the reactor at 200-250°C. These extracted polyol small molecules are usually called dealcoholization, which generally account for 3-15% of the polyol monomer input and are placed in storage tanks. As the type and composition of polyol small molecules used in polyester polyols change, the type, composition and water content of polyol small molecules in dealcoholization also fluctuate, so this kind of dealcoholization is usually treated as liquid waste deal with. In the prior art, the dealcoholation produced is usually collected, and then reacted with dibasic acid and polyol catalysts in the kettle.

CN104558548A discloses a method for preparing adipic acid polyester polyol mixed with recovered alcohol condensate. The disclosed method is to combine the condensate collected in the condensation tank from flowing through the reaction condenser with low-molecular polyols, adipic acid Acid and catalyst are put into the reaction kettle together to produce adipic acid polyester polyol. The disclosed method has a simple synthesis process, and the raw materials are common stable chemical materials on the market. There is no shortage of raw materials. It can not only produce adipic acid polyol Ester polyols, and directly recycle polyol condensate, and do not use water-carrying agents such as toluene and xylene, which avoids the problems of toxicity, environmental pollution, and recycling costs caused by organic solvents, and improves the product yield and reduces Environmental pollution, convenient and feasible process operation. But it does not address the stability of the product application.

In actual production, the type, composition ratio and water content of polyol small molecules in each batch of dealcoholization are all changed, and this change will lead to unstable quality of the prepared polyester polyol product. The water content of dealcoholization is generally between 10% and 40%, and such a high water content will lead to a decrease in single-pot output and low production efficiency.

Therefore, how to develop a stable performance based on dealcoholized polyester polyol, and improve its single-pot output, is crucial.

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a polyester polyol and its preparation method and application. The polyester polyol has high single-pot production capacity, stable product performance, high production efficiency and can be used as polyurethane hard Raw materials such as quality foam, adhesive; The present invention is based on the described polyester polyol of dealcoholization and prior art industry uses the polyester polyol of water-free raw material compared, when being used for polyurethane, can provide close reactivity, foam Density, foam mechanical strength and oxygen index.

For reaching this purpose, the present invention adopts following technical scheme:

In the first aspect, the present invention provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components according to parts by weight:

Polyacid 100 parts

Dealcoholization 100-300 parts

Catalyst 0-0.2 parts, and not equal to 0 parts;

The hydroxyl value of the polyester polyol is 250-500KOH/g, such as 250KOH/g, 300KOH/g, 350KOH/g, 400KOH/g, 450KOH/g, etc.

The polyester polyol product of the present invention based on dealcoholization is stable in performance, and compared with the polyester polyols that do not use water raw materials in the prior art industry, when used in polyurethane, it can provide close reactivity, foam density, foam Mechanical strength and oxygen index.

When the type and composition ratio of small molecule polyols contained in the dealcoholization fluctuate greatly, when the hydroxyl value of the prepared polyester polyol is less than 250mgKOH/g, the physical properties of the polyester polyol will change greatly. For example, with the same molecular weight, the viscosity of the product at room temperature changes by more than 10 times, or even 100 times, and can change from a highly crystalline solid to an amorphous liquid, etc., which will affect downstream use. When the hydroxyl value of the polyester polyol of the present invention is 250 mgKOH/g-500 mgKOH/g, the product viscosity at room temperature varies with the type and composition of the polyol in a small range, and the viscosity change range is small. The higher the hydroxyl value, the smaller the viscosity change, and the higher the temperature, the smaller the viscosity change. In some polyurethane rigid foam, adhesive and coating applications, this general-purpose product with a change in the composition of the polyol raw material but a small change in viscosity is acceptable. And as the hydroxyl value increases, the product needs to use more dealcoholization, the reaction time will be shortened, and the amount of dealcoholization in the factory will decrease.

In the present invention, the parts by weight of the dealcoholization are 100-300 parts, such as 120 parts, 140 parts, 160 parts, 180 parts, 200 parts, 220 parts, 240 parts, 260 parts, 280 parts, etc.

The parts by weight of the catalyst are 0-0.2 parts, and not equal to 0 parts, such as 0.02 parts, 0.04 parts, 0.06 parts, 0.08 parts, 0.1 parts, 0.12 parts, 0.14 parts, 0.16 parts, 0.18 parts, etc.

Preferably, the dealcoholization includes vacuum-removed polyol monomers during the polycondensation reaction of polyester production.

Preferably, the polyol monomers include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, methyl Any one or a combination of at least two of propylene glycol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, glycerin or trimethylolpropane, wherein typical but Non-limiting combinations include: combinations of ethylene glycol and 1,3-propanediol, combinations of 1,2-propanediol, 1,4-butanediol and diethylene glycol, triethylene glycol, methylpropanediol , a combination of 3-methyl-1,5-pentanediol and neopentyl glycol, methylpropanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, Combinations of glycerin and trimethylolpropane, etc.

Preferably, the dealcoholization also includes vacuum removal of water during polycondensation reaction in polyester production.

Preferably, the polybasic acid includes any one or a combination of at least two of succinic acid, adipic acid, sebacic acid, terephthalic acid, phthalic anhydride, isophthalic acid or trimellitic anhydride, wherein typically But non-limiting combinations include: the combination of succinic acid, adipic acid and sebacic acid, the combination of terephthalic acid, phthalic anhydride, isophthalic acid and trimellitic anhydride, the combination of adipic acid, sebacic acid, terephthalic acid, Combinations of phthalic acid, phthalic anhydride and isophthalic acid, etc.

Preferably, the catalyst includes any one or a combination of at least two of stannous octoate, tetrabutyl titanate or tetraisopropyl titanate, wherein typical but non-limiting combinations include: stannous octoate and titanium The combination of tetrabutyl titanate, the combination of tetrabutyl titanate and tetraisopropyl titanate, the combination of stannous octoate, tetrabutyl titanate and tetraisopropyl titanate, etc.

Preferably, the acid value of the polyester polyol is ≤3 mgKOH/g, such as 2.8 mgKOH/g, 2.6 mgKOH/g, 2.4 mgKOH/g, 2.2 mgKOH/g, 2.0 mgKOH/g, etc.

In the present invention, the acid value of the polyester polyol is within a preferred range, and its reactivity is relatively stable. When the acid value is ≤3mgKOH/g and the hydroxyl value is 250mgKOH/g～500mgKOH/g, the polycondensation stage of polyester polyol production can be completed under normal pressure without high vacuum, thus avoiding the output of new dealcoholization .

Second aspect, the present invention provides a kind of preparation method of polyester polyol described in the first aspect, described preparation method comprises the steps:

Under an inert atmosphere, the polybasic acid and the dealcoholization are carried out under the action of a catalyst, followed by a dehydration reaction and a polycondensation reaction to obtain the polyester polyol.

Preferably, the temperature of the dehydration reaction is 140-200°C, such as 150°C, 160°C, 170°C, 180°C, 190°C, etc.;

Preferably, the temperature of the polycondensation reaction is 200-250°C, such as 210°C, 220°C, 230°C, 240°C, etc.;

Preferably, the dehydration reaction and polycondensation reaction are carried out in a reactor;

The reaction kettle is connected with the dealcoholization tanks of other polyester reactors, and the dealcoholization is added to the system at least twice.

In the present invention, in order to further improve production efficiency, according to the output of dealcoholization, the ratio of the number of reactors of conventional polyester polyol products connected with the reactors for preparing polyester polyols by dealcoholization can be designed. Assuming that the volume of the reactor is the same, the output of the average dealcoholization in each still accounts for n% of the total charge, and the average water content of the dealcoholization is m%, and the reactor of its connected conventional polyester polyol product is the same as that using dealcoholization The ratio of the number of reactors preparing polyester polyols is:

When the ratio is less than When the ratio is higher than , there will be a backlog of dealcoholization that cannot be consumed in time.

The preparation method that the present invention takes specifically comprises the following steps:

(1) Put in polybasic acid that can at least meet the minimum production capacity, dealcoholization and catalyst to start the reaction, under the protection of inert gas, at 140-200°C (such as 150°C, 160°C, 170°C, 180°C, 190°C etc.) for dehydration reaction, and then rise to 200-250°C (such as 210°C, 220°C, 230°C, 240°C, etc.) for polycondensation reaction.

(2) When the new dealcoholization is produced and put into the reactor, the corresponding amount of polybasic acid and catalyst are put in together, and the reaction is carried out directly at 200-250°C (such as 210°C, 220°C, 230°C, 240°C, etc.) , until the designed production capacity and acid value are lower than 3mgKOH/g (such as 2.8mgKOH/g, 2.6mgKOH/g, 2.4mgKOH/g, 2.2mgKOH/g, etc.), and the hydroxyl value is 250mgKOH/g～500mgKOH/g (eg 300mgKOH/g, 350mgKOH/g, 400mgKOH/g, 450mgKOH/g, etc.) requirements.

The preparation method of the present invention can cool down and stop the reaction after the last batch of dealcoholization enters the reactor for 4 hours.

In the present invention, compared with waiting to produce a still polyester polyol and needs the total demand of dealcoholization to collect and put into reactor to start reaction again, the production method that high-temperature reaction of the present invention carries out simultaneously with continuous feed can improve Time efficiency, reducing the inventory of dealcoholization in the factory, and greatly increasing the output of single-pot products.

In a third aspect, the present invention provides a polyester, the raw material for the preparation of the polyester includes the polyester polyol described in the first aspect.

In a fourth aspect, the present invention provides an application of the polyester polyol described in the first aspect in polyurethane rigid foam or adhesive.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The polyester polyol of the present invention has high single-pot production capacity, stable product performance, high production efficiency and can be used as raw materials such as polyurethane rigid foams and adhesives.

(2) Compared with the polyester polyols of the prior art industry using non-water raw materials, the polyester polyols based on dealcoholization of the present invention can provide close reactivity, foam density, and foam mechanical properties when used in polyurethane. strength and oxygen index.

Detailed ways

The technical solutions of the present invention will be further described below through specific embodiments. It should be clear to those skilled in the art that the examples are only for helping to understand the present invention, and should not be regarded as specific limitations on the present invention.

Example 1

This embodiment provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The dealcoholization 1 is composed of 31% water, 20% ethylene glycol, 15% 1,4-butanediol and 34% diethylene glycol; dealcoholization 2 is composed of 13% water, 43% 1,4-butanediol and 44% of 1,6-hexanediol, dealcoholation 3 is composed of 20% water, 34% ethylene glycol and 46% diethylene glycol; dealcoholation 4 is composed of 35% water, 11% neopentyl glycol and 54% diethylene glycol; dealcoholization 5 is composed of 38% water and 62% ethylene glycol; dealcoholization 6 is composed of 25% water, 21 % ethylene glycol, 14% propylene glycol and 40% diethylene glycol; dealcoholization 7 is composed of 26% water, 43% ethylene glycol and 31% 1,4-butanediol; Alcohol 8 consists of 23% water and 77% diethylene glycol; dealcoholation 9 consists of 37% water, 15% ethylene glycol, 43% diethylene glycol and 5% 1,6 - Composed of hexanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) 850g phthalic anhydride, 1650g dealcoholization 1 and 0.2g tetrabutyl titanate are added in a 5 kg reactor;

(2) Increase the temperature to 220°C under nitrogen protection, and then put 170g of phthalic anhydride, 330g of dealcoholization 2 to dealcoholization 9 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes until the kettle is full. Separation and removal of the condensed water and small molecule polyols through the fractionation tower connected to the reaction kettle, stop the reaction when the acid value is lower than 3mgKOH/g, and obtain 4758g polyester polyol with a hydroxyl value of 408mgKOH/g and a viscosity of 3890cPs /25°C.

Example 2

This embodiment provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The dealcoholization 10 is composed of 18% water, 44% 1,2-propanediol and 38% neopentyl glycol; dealcoholization 11 is composed of 27% water, 12% ethylene glycol, 33% 1, Composed of 4-butanediol and 28% diethylene glycol; dealcoholized 12 consists of 32% water, 23% 1,2-propanediol, 31% 1,4-butanediol and 14% neopentyldiol Alcohol composition; dealcoholization 13 consists of 21% water, 30% ethylene glycol and 49% diethylene glycol; dealcoholization 14 consists of 15% water, 34% 1,4-butanediol and 51% Dealcoholization 15 is composed of 28% water, 12% diethylene glycol and 60% neopentyl glycol; dealcoholization 16 is composed of 15% water, 64% diethylene glycol Diethylene glycol and 21% neopentyl glycol; dealcoholized 17 consists of 25% water and 75% neopentyl glycol; dealcoholized 18 consists of 19% water, 28% ethylene glycol and 53% 1 , composed of 2-propanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 900g phthalic anhydride, 1600g dealcoholized 10 and 0.2g tetrabutyl titanate and join in 5 kilograms of reactors;

(2) Increase the temperature to 220°C under nitrogen protection, and then put 180g of phthalic anhydride, 320g of dealcoholization 11 to dealcoholization 18 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes, and pass through the reaction kettle. The connected fractionation tower separates and removes the condensed water and small molecule polyols. When the reactor still has 400g raw material feeding space, drop into phthalic anhydride 144g, dealcoholization 256g and tetrabutyl titanate 0.032g, stop reaction when acid value is lower than 3mgKOH/g, finally obtain 4812g polyester polyol, its The hydroxyl value is 418mgKOH/g, and the viscosity is 3467cps/25°C.

Example 3

This embodiment provides a polyester polyol, the raw materials for the preparation of the polyester polyol include the following components: adipic acid, dealcoholization and tetrabutyl titanate;

The dealcoholization 19 is composed of 22% water, 13% neopentyl glycol, 30% 1,6-hexanediol and 35% methylpropanediol; dealcoholization 20 is composed of 35% water and 65% 1 , composed of 4-butanediol; dealcoholized 21 consists of 21% water, 36% 1,4-butanediol and 43% 1,6-hexanediol; dealcoholized 22 consists of 19% water, 62% Diethylene glycol and 19% of 1,6-hexanediol; dealcoholization 23 consists of 19% of water, 60% of 1,4-butanediol and 21% of neopentyl glycol, 30% of 1 , 6-hexanediol and 35% of methylpropanediol; dealcoholized 24 is composed of 28% of water, 24% of diethylene glycol and 48% of neopentyl glycol; dealcoholized 25 is composed of 20% of water, Composed of 11% diethylene glycol and 69% 1,6-hexanediol; dealcoholized 26 consists of 21% water, 23% 1,4-butanediol and 56% diethylene glycol ; Dealcohol 27 consists of 25% water, 5% 1,4-butanediol and 70% neopentyl glycol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 1000g of adipic acid, 1500g of dealcoholized 19 and 0.2g of tetrabutyl titanate and join in a 5 kg reactor;

(2) Increase the temperature to 220°C under nitrogen protection, and then put 200g of adipic acid, 300g of dealcoholization 20 to dealcoholization 27 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes, and connect it through the reaction kettle. The fractionation tower separates and removes the condensed water and small molecule polyols. When the reactor still has 400g of raw material feeding space, put in 160g of adipic acid, 240g of dealcoholization and 0.032g of tetrabutyl titanate, stop the reaction when the acid value is lower than 3mgKOH/g, finally obtain 4823g of polyester polyol, its hydroxyl The value is 252mgKOH/g, and the viscosity is 1735cps/25°C.

Example 4

The difference between this embodiment and Example 1 is that the dealcoholization is collected by the dealcoholization tank connected to the reactor in Example 1, and the dealcoholization 28 is composed of 29% water, 21% ethylene glycol, 11% 1,4-butanediol, 33% diethylene glycol, 1% 1,2-propanediol, 1% neopentyl glycol and 4% 1,6-hexanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) 850g phthalic anhydride, 1650g dealcoholized 28 and 0.2g tetrabutyl titanate are added to a 5 kg reactor;

(2) Increase the temperature to 220°C under nitrogen protection, then put 170g of phthalic anhydride, 330g of dealcoholized 28 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes until the kettle is full, and pass through the reaction kettle. The connected fractionation tower separates and removes the condensed water and small molecular polyols. When the acid value is lower than 3mgKOH/g, the reaction is stopped to obtain 4683g polyester polyol with a hydroxyl value of 419mgKOH/g and a viscosity of 3656cPs/25°C.

Example 5

This embodiment provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The dealcoholization 28 consists of 29% water, 21% ethylene glycol, 11% 1,4-butanediol, 33% diethylene glycol, 1% 1,2-propanediol, 1% of neopentyl glycol and 4% of 1,6-hexanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 1700g phthalic anhydride, 3300g dealcoholized 28 and 0.4g tetrabutyl titanate and join in a 5 kg reactor;

(2) Heating up to 220°C under nitrogen protection, and separating and removing the condensed water and small molecular polyols produced by the fractionation tower connected to the reaction kettle. Stop the reaction when the acid value is lower than 3mgKOH/g, and finally obtain 3687g polyester polyol with a hydroxyl value of 420mgKOH/g and a viscosity of 3775cPs/25°C.

Example 6

This embodiment provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The difference between this embodiment and Example 2 is that the dealcoholization is collected by the dealcoholization tank connected to the reactor in Example 2, and the dealcoholization 29 is composed of 21% water, 5% ethylene glycol , 23% of 1,2-propanediol, 8% of 1,4-butanediol, 16% of diethylene glycol and 28% of neopentyl glycol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 1800g of phthalic anhydride, 3200g of dealcoholized 29 and 0.4g of tetrabutyl titanate and join in a 5 kg reactor;

(2) Heating up to 220°C under nitrogen protection, and separating and removing the condensed water and small molecular polyols produced by the fractionation tower connected to the reaction kettle. Stop the reaction when the acid value is lower than 3mgKOH/g, and finally obtain 4035g polyester polyol with a hydroxyl value of 412mgKOH/g and a viscosity of 3610cPs/25°C.

Example 7

This embodiment provides a polyester polyol, the raw materials for the preparation of the polyester polyol include the following components: adipic acid, dealcoholization and tetrabutyl titanate;

The difference between this embodiment and Example 3 is that the de-alcoholization is collected by the de-alcoholization tank connected to the reactor in Example 3, and the de-alcoholization 30 is composed of 23% water, 15% 1,4- Butanediol, 12% diethylene glycol, 16% neopentyl glycol, 21% 1,6-hexanediol and 13% methylpropanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 2000g of adipic acid, 3000g of dealcoholized 30 and 0.4g of tetrabutyl titanate and join in a 5 kg reactor;

(2) Heating up to 220°C under nitrogen protection, and separating and removing the condensed water and small molecular polyols produced by the fractionation tower connected to the reaction kettle. When the value is lower than 3mgKOH/g, the reaction is stopped, and finally 3593g of polyester polyol is obtained with a hydroxyl value of 255mgKOH/g and a viscosity of 1833cPs/25°C.

Comparative example 1

This comparative example provides a kind of polyester polyol, the preparation raw material of described polyester polyol comprises the following components: phthalic anhydride, ethylene glycol, diethylene glycol and tetrabutyl titanate;

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) Get 2140g of phthalic anhydride, 720g of ethylene glycol, 2140g of diethylene glycol, and 0.4g of tetrabutyl titanate and join in a 5 kg reactor;

(2) Heating up to 220° C. under nitrogen protection, and separating and removing the generated condensation water and small molecular polyols through the fractionation tower connected to the reaction kettle. Stop the reaction when the acid value is lower than 3mgKOH/g, and finally obtain 4496g polyester polyol with a hydroxyl value of 397mgKOH/g and a viscosity of 1910cPs/25°C.

Comparative example 2

The difference between this comparative example and Example 1 is that the hydroxyl value of the polyester polyol is 197mgKOH/g, specifically as follows:

The raw materials for the preparation of the polyester polyol include the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The dealcoholization 28 consists of 29% water, 21% ethylene glycol, 11% 1,4-butanediol, 33% diethylene glycol, 1% 1,2-propanediol, 1% Composition of neopentyl glycol and 4% 1,6-hexanediol

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) 1100g phthalic anhydride, 1400g dealcoholized 28 and 0.2g tetrabutyl titanate are added to a 5 kg reactor;

(2) Increase the temperature to 220°C under nitrogen protection, then put 170g of 220g of phthalic anhydride, 280g of dealcoholized 28 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes until the kettle is full, and pass through the reaction kettle The fractionation tower connected above separates and removes the condensed water and small molecule polyols. When the acid value is lower than 3mgKOH/g, the reaction is stopped, and 4683g polyester polyol is obtained. The hydroxyl value is 197mgKOH/g, and the viscosity is 218770cPs/25℃ .

Comparative example 3

The difference between this comparative example and Example 1 is that the hydroxyl value of the polyester polyol is 550mgKOH/g, specifically as follows:

The raw materials for the preparation of the polyester polyol include the following components: phthalic anhydride, dealcoholization and tetrabutyl titanate;

The dealcoholization 28 consists of 29% water, 21% ethylene glycol, 11% 1,4-butanediol, 33% diethylene glycol, 1% 1,2-propanediol, 1% of neopentyl glycol and 4% of 1,6-hexanediol.

Described polyester polyol is obtained by following preparation method, and described preparation method comprises the steps:

(1) 730g of phthalic anhydride, 1770g of dealcoholized 28 and 0.2g of tetrabutyl titanate were added to a 5 kg reactor;

(2) Heat up to 220°C under nitrogen protection, then put 146g of phthalic anhydride, 354g of dealcoholized 28 and 0.04g of tetrabutyl titanate into the reaction kettle every 20 minutes until the kettle is full, and pass through the reaction kettle The connected fractionation tower separates and removes the condensed water and small molecular polyols. When the acid value is lower than 3mgKOH/g, the reaction is stopped to obtain 4782g polyester polyol with a hydroxyl value of 558mgKOH/g and a viscosity of 473cPs/25°C.

Performance Testing

1, the polyester polyol described in embodiment 1-7 and comparative example 1-3 is carried out following test:

(1) Single kettle output (%): It is the weight ratio of the output to the full kettle feed.

(2) Hydroxyl value (mgKOH/g): refer to the method specified in HG/T 2709-1995.

(3) Viscosity (cps) at 25°C: refer to the method specified in GB/T 22235-2008.

The test results are summarized in Table 1.

Table 1

Analysis of the data in Table 1 shows that the single-pot output of the polyester polyol of the present invention is above 72%, and the viscosity is between 1735-3890cPs at 25°C.

In the preferred range (taking Examples 1-4 as an example), the single-pot yield of the polyester polyol of the present invention is above 94%, and the viscosity at 25° C. is between 1735-3890 cPs.

Generally, the yield of polyester polyols with a hydroxyl value of 250 mgKOH/g to 500 mgKOH/g prepared by dealcoholization containing water is 60%-85%. Assuming that a 20-ton reactor is used, the dealcoholization produced by each kettle is 1 ton. If the dealcoholization is put into a 20-ton production kettle at one time, the weight of the final product produced is 12-17 tons. If it is input in batches, the weight of the final product can reach 19.2-19.7 tons based on the calculation that the input amount of the last batch of dealcoholization and dibasic acid is 2 tons.

Analysis of Comparative Example 1 and Example 1 shows that compared with the polyester polyol of Comparative Example 1, the dealcohol-based polyester polyol of the present invention can provide similar single-pot output, viscosity and hydroxyl value.

Analysis of Comparative Example 2-3 and Example 1 shows that the viscosity of Comparative Example 2-3 is too large or too small, which will affect its application, and its performance is not as good as that of Example 1, which proves that the hydroxyl value of the polyester polyol is at 250-500mgKOH/ Better performance in the g range.

Analyzing Example 5 and Example 1, Example 6 and Example 2, and Example 7 and Example 3, it can be seen that under the situation that the composition ratio of the feed intake does not change, the production of polyester polyol products close to the hydroxyl value, the implementation of high temperature The continuous feed while reacting is higher than the single-pot production of one-time feeding, and the viscosity change is small.

2. The polyester polyol described in Examples 1-2 and Comparative Example 1 is formed into polyurethane, and its foaming performance is tested. The test methods adopted for compressive strength and free foam density refer to: GB/T 8813-2020, oxygen index The test method refers to: GB/T 2409.2-2009.

Specifically, the preparation method of polyurethane comprises the steps:

With 100 parts by mass of polyester polyol, 15 parts by mass of TCPP, silicone oil (trade name B8462) 2 parts by mass, 1 part by mass of water, amine catalyst (trade name /> 8) 0.5 parts by mass and potassium salt catalyst (trade name /> K-15) 1 part by mass, 12 parts by mass of a blowing agent n-pentane, and 190 parts by mass of polymethylene polyphenylisocyanate (trade name WANNATE PM-200) were foamed to obtain the polyurethane.

The test results are summarized in Table 2.

Table 2

foam properties Example 1 Example 2 Comparative example 1 Enlightenment time (seconds) 25 26 twenty four Gel time (seconds) 52 50 52 Free foam density (kg/m3) 46 45 45 Compressive strength (kPa) 246 257 252 Oxygen Index(%) 25.2 25.1 25.1

Analysis of the data in Table 2 shows that compared with the polyester polyol of Comparative Example 1, the dealcohol-based polyester polyol of the present invention can provide close reactivity, foam density, foam mechanical strength and oxygen index.

The present invention illustrates the detailed methods of the present invention through the above examples, but the present invention is not limited to the above detailed methods, that is, it does not mean that the present invention must rely on the above detailed methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. a polyester polyol, is characterized in that, the preparation raw material of described polyester polyol comprises following component according to parts by weight: Polyacid 100 parts Dealcoholization 100-300 parts Catalyst 0-0.2 parts, and not equal to 0 parts; The hydroxyl value of the polyester polyol is 250-500KOH/g. 2. polyester polyol according to claim 1, is characterized in that, described dealcoholization comprises the polyol monomer that vacuum removes when polyester production carries out polycondensation reaction; The polyol monomer includes ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, triethylene glycol, methyl propylene glycol, 3 -Any one or a combination of at least two of methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, glycerol or trimethylolpropane; The dealcoholization also includes the water removed in vacuum during polycondensation reaction in polyester production. 3. polyester polyol according to claim 1, is characterized in that, described polybasic acid comprises succinic acid, adipic acid, sebacic acid, terephthalic acid, phthalic anhydride, isophthalic acid or Any one or a combination of at least two of trimellitic anhydrides. 4. The polyester polyol according to claim 1, wherein the catalyst comprises any one or a combination of at least two of stannous octoate, tetrabutyl titanate or tetraisopropyl titanate. 5. The polyester polyol according to claim 1, characterized in that, the acid value of the polyester polyol is ≤3mgKOH/g. 6. a preparation method of the polyester polyol described in any one of claim 1-5, is characterized in that, described preparation method comprises the steps: Under an inert atmosphere, the polybasic acid and the dealcoholization are carried out under the action of a catalyst, followed by a dehydration reaction and a polycondensation reaction to obtain the polyester polyol. 7. The preparation method according to claim 6, characterized in that, the temperature of the dehydration reaction is 140-200°C. 8. The preparation method according to claim 6, characterized in that, the temperature of the polycondensation reaction is 200-250°C. 9. preparation method according to claim 6, is characterized in that, described dehydration reaction and polycondensation reaction are carried out in reactor; The reaction kettle is connected with the dealcoholization tanks of other polyester reactors, and the dealcoholization is added to the system at least twice. 10. an application of the polyester polyol described in any one of claims 1-5 in rigid polyurethane foam or adhesive.